#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>

struct ListNode
{
	struct ListNode* next;
	int val;
};

struct ListNode* middleNode(struct ListNode* head)
{
	struct ListNode* slow, * fast;
	slow = fast = head;
	while (fast && fast->next)
	{
		slow = slow->next;
		fast = fast->next->next;
	}
	return slow;
}
int main()
{
	return 0;
}